Adjustable impact casing for a shaft furnace

ABSTRACT

An adjustable impact casing for use in a shaft furnace is formed of a plurality of upwardly extending segments. The segments are arranged in an inner circular row enclosed by an outer circular row. In each row, segments are spaced angularly apart and are offset to the segments in the other row with their upwardly extending lateral edges arranged in overlapping and substantially contacting relationship. The segments are pivotally supported about axes extending transversely of the upright axis of the casing and as segments in the inner row are secured to one adjustment drive arrangement while the segments in the outer row are secured to another adjustment drive arrangement. A control circuit is connected to the adjustment drive arrangements for regulating the movement of the segments between spaced positions. Initially, the segments in one of the rows are spaced from the segments in the other row. Then, the two rows are moved together toward a new position with one row of segments moved into the new position. Finally, the other row of segments is displaced into contact with the row of segments already in position.

United States Patent [1 1 Schwerdtfeger et al.

[ Oct. 30, 1973 ADJUSTABLE IMPACT CASING FOR A SHAFT FURNACE [75] Inventors: Gunter Schwerdtfeger, Oberhausen Rhineland; Bruno Karnmerling, Oberhausen, both of Germany [73] Assignee: Gutehoffnungshuette Sterkrade A.G.

[22] Filed: June 22, 1972 [21] Appl. No.: 265,234

[30] Foreign Application Priority Data Primary ExaminerGerald A. Dost Att0rneyDavid Toren et al.

[5 7] ABSTRACT An adjustable impact casing for use in a shaft furnace is formed of a plurality of upwardly extending segments. The segments are arranged in an inner circular row enclosed by an outer circular row. In each row, segments are spaced angularly apart and are offset to the segments in the other row with their upwardly extending lateral edges arranged in overlapping and substantially contacting relationship. The segments are pivotally supported about axes extending transversely of the upright axis of the casing and as segments in the inner row are secured to one adjustment drive arrangement while the segments in the outer row are secured to another adjustment drive arrangement. A control circuit is connected to the adjustment drive arrangements for regulating the movement of the segments between spaced positions. Initially, the segments in one of the rows are spaced from the segments in the other row. Then, the two rows are moved together toward a new position with one row of segments moved into the new position. Finally, the other row of segments is displaced into contact with the row of segments already in position.

7 Claims, 4 Drawing Figures Patented Oct. 30, 1973 3,768,791

3 Sheets-Sheet 1 Patented Oct. 30, 1973 3,768,791

3 Sheets-Sheet i2 Patented Oct. 30, 1973 3 Sheets-Sheet F fi ADJUSTABLE IMPACT CASING FOR A SHAFT FURNACE SUMMARY OF THE INVENTION The present invention is directed to an adjustable protection or impact casing in a shaft furnace, particularly for use in blast furnaces, and, more especially, it provides an arrangement for moving the casing, formed of two circular rows of individual segments, between two spaced positions where initially one row of segments is moved relative to the other, then both rows are moved together toward the new position and finally one of the rows is moved into contact with the other for completing the movement into the new position.

The present invention is an improvement over the adjustable impact casing disclosed in our co-pending application Ser. No. 144,978 filed May 17, 1971 and now U.S. Pat. No. 3,693,952.

The adjustable impact casing embodying the present invention includes an inner circular row of segments disposed radially inwardly from an outer circular row of segments with the segments in the two rows disposed in overlapping contacting engagement along their lateral edges. A push rod is connected to the outer surface of each segment for moving it into the desired position. Linkage assemblies connect the push rods to adjustment drives for locating the segments in position. By means of a control circuit, after first spacing the segments in one of the rows from the segments in the other row, the segments in both rows are shifted together until the segments in one row are in the new position and then the segments in the other row are moved into contact with them.

This arrangement is suitable for adjusting the position of an impact casing, especially where large adjustment paths are involved, for example, in a blast furnace having a throat diameter of 11 m with an adjustment range of about 1,900 mm. The individual segments for the impact casing are formed with a fixed radius. As a result, when a simultaneous adjustment of all of the segments is made, a radial clearance must be provided between the segments and the extent of the clearance varies directly with the length of the adjustment path to be travelled. Because of the necessary clearance, materials charged into the furnace may become stuck between the segments thereby hindering or preventing the required adjustment of the impact casing. In the impact casing disclosed in the prior application, the segments in the inner and outer rows were moved separately with a time delay provided between the movement of each row. As a result, one of the rows had to be moved into the new position before the other row could be moved.

Therefore, it is the primary object of the present invention to simplify the movement of the segments in the inner and outer rows as compared to that described in the prior application. Accordingly, the adjustable impact casing, which can be displaced over a wide range, affords an acceleration of the adjustment process.

In accordance with the present invention, a control arrangement is afforded in which one of the rows of segments is initially displaced out of contact with the other row, then both rows are moved toward the new position with one of the rows being located in the new position, and finally the other row is moved into the new position in contact with the previously positioned row. As a result, during the adjustment operation a constant spacing is maintained between the two rows of segments as they are moved through the major portion of the adjustment path.

By moving both rows of segments at the same time over the major portion of the adjustment path, it is possible to complete the adjustment operation in a shorter time. The initial and final time shift of one of the rows relative to the other insures all the advantages obtained with the arrangement of the adjustable impact casing described in the prior application.

In the time sequence of the adjustment operation, first one of the rows is moved relative to the other so that a spacing is provided between the two rows of segments. During the next time period both rows of the segments are moved simultaneously and at about the same speed. In the final portion of the time period covered by the move, it is necessary for only one of the rows of segments to be moved into contact with the other to complete the adjustment operation.

In one embodiment of the invention, the push rods connected to the segments in the inner row and the push rods connected to the segments in the outer row are each associated with a ring to which adjustment drives are fixed. At the outset of the adjustment operation, the adjustment drives of one ring can be actuated for spacing one row of the segments from the other in the direction in which the adjustment movement is to be made. The row of segments initially provided with a lead toward the new position, is moved into the new position at the end of the movement of both rows so that the other row is spaced from or has a lag relative to the new position. Therefore, to complete the adjustment operation, the other ring is moved by the adjustment drives, as the final step in the adjustment operation, to place the row of segments associated with the ring into contacting engagement with the segments in the row located in the new position. As an alternative, the adjustment drives which displace one of the rings so that its associated row of segments is moved into a leading position, can be moved through the new position so that a movement in the opposite direction of the adjustment drives is required to locate the initially displaced row in the opposite direction into contact with the other row of segments at the new position. In the first case the row of segments initially moved out of contact is then moved into the desired position with the other row being moved into contact with it as the final step of the adjustment operation. In the second case, the row of segments initially moved out of contact is displaced through the new position with the other row of segments being located in the new position and finally the initially displaced row is moved into contact with the other row to complete the adjustment operation.

As an alternative to the arrangement of the rings and adjustment drives mentioned above, one adjustment drive group can be arranged to move both of the rings while the other adjustment drive group moves one ring relative to the other for providing its associated row of segments with a lead or a lag relative to the desired direction of movement of the segments. Accordingly, depending on the direction of adjustment movement, the necessary lead or lag is provided by the one adjustment drive group which is then locked or held in position and the movement of both rows of segments is provided by the other adjustment drive group. At the completion of the adjustment move, the one of the adjustment drive groups moves its associated row of segments into contact with the other row for completing the adjustment move.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a vertical partial section through the throat of a blast furnace having an impact casing incorporating the present invention;

FIG. 2 is a view similar to FIG. 1 of another embodiment of the present invention;

FIG. 3 is a view taken along lines IIII in FIG. 1; and

FIG. 4 is a developed side view of the arrangement shown in FIG. I.

DETAILED DESCRIPTION OF THE INVENTION -In FIGS. 1 and 2, the upper part ofa blast furnace is illustrated with an adjustable impact casing in accordance with the present invention. The charge is directed into the furnace through its throat I when the furnace-top bell 2 is lowered, note the closed position shown in full lines and the lowered or opened position shown in dot-dashed lines. Based on the diameter of the impact casing and the angular disposition of its surface, the charge directed into the furnace is given a certain profile as is indicated in FIGS. 1 and 2.

As shown in FIG. 3, the impact casing is formed of a radially inner row of impact-resistant segments 3 each having a fixed radius and a radially outer row of impact-resistant segments 3a each having a fixed radius and with the lateral upright edges of adjacent segments disposed in overlapping relationship. The segments 3, 3a in each row are angularly spaced apart from one another so that the casing is provided by alternating segments in the inner and outer row. The fixed radius of the segments is determined based on the furnace radius for an intermediate position in the adjustment range of the segments.

Each of the segments 3, 3a is suspended within the shaft casing 4 of the blast furnace by means of bars or rods 5 which are pivotally connected adjacent their upper ends to the inner surface of the shaft casing. Mounted on the outwardly facing side of each segment is a mounting member 6 and a push rod 7 is connected to each mounting member in a pivotal manner. Furnace wall 9 of the shaft casing disposed opposite the impact casing has a plurality of funnel-shaped openings 8 with a push rod 7 extending outwardly through each of the openings. At its outer end, each push rod 7 is secured, through a hinge joint, to one arm 10 of an angle lever and the other arm 11 of the angle lever is connected to the end of a pull rod 12, 12a.

Located below the openings 8 on the outer surface of the shaft casing 4 are a pair of rings 13, 13a, encircling the furnace. Ring 13 is positioned above ring 13a. The rings 13, 130 can be lifted and lowered in the axial direction of the furnace by means of adjusting drives which are mounted on the exterior surface of the shaft casing 4. In the arrangement shown in FIG. 1, the adjusting drive for ring 13 consists of a hydraulic cylinder 14 secured to the outer surface of the shaft casing with a piston rod 15 extending downwardly from the hydraulic cylinder and connected to the upper surface of the ring 13. As the ring 13 is moved in the axial direction of the furnace, its movements are transmitted to the segments 3 of the radially inner row of the impact casing by way of the pull rod 12, the arms 10 and 11 of the angle lever, and the push rod 7. Similarly, the adjusting drive for the ring 13a is provided by a hydraulic cylinder 14a fixed to the outer surface of the shaft casing and a piston rod 15a extending upwardly from the hydraulic cylinder and connected to the lower surface of the ring 13a. The movement of ring is transmitted to the radially outer row of segments 30 by means of the pull rods 12a and the arms l0, ll of the angle levers, and the push rods 7, associated with the pull rods 12a.

In the arrangement shown in FIG. I, the segments 3, 3a, of the impact casing are adjusted from one position to another in the following manner. When inwardly directed travel of the impact casing is to be effected, the hydraulic cylinder 14 is moved in the direction of the furnace axis through a control circuit, not shown, and, in turn, displaces the inner row of segments 3 in the inward direction for a short distance out of contact with the segments 3a in the outer row. With the inner and outer rows of segments spaced apart, the hydraulic cylinder 14a is actuated and along with the other hydraulic cylinder 14 combines to lift both of the rings 13, 13a simultaneously in the same direction and at approximately the same speed. When the segments 3 of the inner row reach the new position, the movement provided by the hydraulic cylinder 14 and piston rod 15 is discontinued. However, the hydraulic cylinders 14a and their associated piston rods 15a continue to displace the segments 3a until they are moved into contact with the segments 3 already in position for completing the adjustment movement. When the impact casing is to be displaced radially outwardly, the sequence described above is reversed and initially the hydraulic cylinders 14a are actuated for affording a lead, time-wise, to the segments 3a in the direction of adjustment movement. During the major portion of the movement, the segments 3, 3a are moved together until the segments 3a reach the new position at which point in time the segments 3 of the inner row lag the segments 3a relative to the new position. The adjustment operation is completed as the segments 3 are moved into contact with the segments 311.

To simplify the adjustment movement of the impact casing, only one of the adjusting drives provided by the hydraulic cylinder-piston rod arrangement associated with one of the rings 13, 13a can be used for providing either a lead or lag to the row of segments associated with the ring in carrying out the adjustment movement. For instance, if only the hydraulic cylinders 14a and piston rods 15a are to be used in providing the lead and lag, then during inward movement of the segments, the ring 13a is displaced so that the segments 3a are moved in the opposite direction to the intended movement a short distance outwardly from the segments 3. Accordingly, the inner and outer rows of segments are spaced apart. For the major portion of the adjustment movement, both of the rings are moved by their associated hydraulic cylinders-piston rods until the inner row of segments 3 has reached the new position and the outer row of segments is still spaced outwardly from the position. With the movement provided by the hydraulic cylinders l4 and piston rods discontinued, the outer row of segments 3 a are moved inwardly into contact with the segments 3 for completing the adjustment operation. On the other hand, if the impact casing is to be displaced radially outwardly, then the segments 3a are provided with a lead, that is, they are moved into an outwardly spaced position relative to the segments 3 at the commencement of the adjustment operation before both rows of segments 3, 3a are moved simultaneously in the outward direction until the segments 3 are in the new position at which point in time the operation of the hydraulic cylinders 14 and piston rods 15 is discontinued and the movement of the hydraulic cylinders 14a and piston rods 15a is reversed for returning the segments 3a inwardly into contact with the segments 3 located in the new position.

In the embodiment disclosed in FIG. 2, the linkage assembly including the push rods 7 between the segments 3, 3a and the rings are the same, however, the ring arrangement is different with ring 16 for moving the segments 3 spaced below ring 16a which moves the segments 3a. Pull rods 12 are attached to ring 16 which, in turn, is displaced in the axial direction of the furnace by a series of hydraulic cylinders 17 and piston rods 18 located below the ring. Extending between the upper surface of ring 16 and the lower surface ring 16a is a series of hydraulic cylinders 17a and piston rods 18a for affording relative movement between the two rings. The pull rods 12a extend upwardly from the ring 16a for moving the segments 3a in the adjustment direction. When using the arrangement shown in FIG. 2, the adjusting drives provided by the hydraulic cylinders 17a and piston rods 18a afford either a lead or lag to the segments 3a and then with the cylinders 17a and piston rods 18a held in position the other adjusting drive afforded by the hydraulic cylinders 17 and the piston rods 18 moves both of the rings either upwardly or downwardly for moving both rows of segments simultaneously toward the new position with the inner row of segments being located at the end of the movement in the new position. To complete the adjustment movement, the segments 3a of the outer row are then moved into contact with the segments 3 of the inner row by again displacing ring 16a relative to ring 16. For instance, when the impact casing is to be moved inwardly, initially, the outer segments are displaced outwardly relative to the inner segments providing a distance between the two segment rows. With the spacing between the segment rows established, the hydraulic cylinders 17a and piston rods 18a are held in position and the hydraulic cylinders 17 and piston rods 18 effect the inward movement of both rows of segments. When the inward movement provided by the hydraulic cylinder 17 and piston rods 18 is completed, the segments 3 are in the new position and the adjusting drive operation is cut-off. To complete the positioning of the impact casing, the hydraulic cylinders 17a and piston rods 18a are again actuated, providing relative movement between the rings 16, 16a, and moving the segments 3a into contact with the already positioned segments 3. When the direction of movement of the impact casing is reversed, that is, when it is moved radially outwardly, the outer segments 3a are moved first in the outward direction to provide a spacing between the outer and inner rows of segments and then both rows are moved simultaneously with the outer row passing through the new position and the inner row of segments being located in the new position. Accordingly, to complete the adjustment operation, the relative position between the rings 16, 16a is adjusted by the hydraulic cylinders 17a and piston rods 18a to move the outer segments 3a into contact with the inner segments 3.

In each of these operations, a control circuit connected to the respective hydraulic cylinders-piston rods of the adjusting drives provides first a lead or lag to one of the inner and outer rows of segments, then causes both rows of segments to move simultaneously with one of them being moved into the new position at which point one of the adjusting drives is shutdown while the other adjusting drive is continued in operation until the other row of segments is moved into contact in the new position.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

1. An adjustable impact casing for use in a shaft furnace, particularly in a blast furnace, said casing having an upright axis and comprising a plurality of angularly spaced apart first arcuate segments forming an inner row about the casing axis, a plurality of angularly spaced apart second segments forming an outer row about the casing axis and disposed contiguous to said inner row, the axes of said first segments and second segments extending in the direction of the casing axis and offset relative to one another and said first segments and second segments having their lateral edges extending in the direction of the casing axis arranged in overlapping substantially contacting relationship so that said inner row and outer row of segments form a continuous casing surface, means for supporting said first and second segments, each of said first and second segments pivotally mounted on said means adjacent the upper ends of the segments, a plurality of push rods extending transversely of the casing axis and each said push rod secured to a different one of said first and second segments, wherein the improvement comprises means for movably positioning said first and second segments from a first position to a second position in both of which positions said first segments and second segments are in contact by initially displacing one of said first segments and second segments from the first position out of contact from and into spaced relationship with the other then displacing said first segments and second segments together in the same spaced relationship toward the second position and locating one of said first and second segments in the second position at the completion of the second displacement and thirdly displacing the other one of said first segments and second segments into the second position and into contact with the one of said first segments and second segments located in the second position.

2. An adjustable impact casing, as set forth in claim 1, wherein said means for movably positioning said first segments and second segments includes control means for effecting the time sequence of the initial displacement, second displacement and third displacement of said first segments and second segments.

3. An adjustable impact casing, as set forth in claim 1, wherein said means for movably positioning said first segments and second segments includes a pair of rings concentrically disposed about the axis of said casing and located radially outwardly from said first segments and second segments, one of said rings located above the other said ring, linkage means interconnecting one of said rings to said push rods for displacing said first segments and the other of said rings to said push rods for displacing said second segments, first adjustment drive means connected to one of said rings for moving said ring in the axial direction of said casing, second adjustment drive means connected to the other of said rings for moving said ring in the axial direction of said casing, and control means associated with said first and second adjustment means for initially displacing one of said first and second segments out of contact with one another followed by moving both of said first and second segments together and finally displacing the other one of said first and second segments into contact with the other.

4. An adjustable impact casing, as set forth in claim 3, wherein said first adjustment drive means comprises a first hydraulic cylinder-piston rod assembly connected at one end to said casing and at its other end to the one of said rings and said second adjustment drive means comprises a second hydraulic cylinder-piston rod assembly connected at one end to said casing and at its other end to the other said ring.

5. An adjustable impact casing, as set forth in claim 1, wherein said means for movably positioning said first segments and second segments includes a pair of rings concentrically disposed about the axis of said casing and located radially outwardly from said first segments and second segments, one of said rings located above the other said ring, linkage means interconnecting one of said rings to said push rods for displacing said first segments and the other of said rings to said push rods for displacing said second segments, first adjustment drive means connected to one of said rings for moving said ring in the axial direction of said casing, second adjustment drive means connected to the other of said rings for moving said ring in the axial direction of said casing, and control means associated with said first and second adjustment means for initially displacing the ones of said first segments and second segments closer to the second position in the direction of the second position in spaced relationship to the other ones of said first segments and second segments, followed by moving both of said first segments and second segments together until the other ones of said first segments and second segments are in the second position and finally displacing the ones of said first segments and second segments in the opposite direction into the second posi' tion and into contact with the other ones of said first segments and second segments located in the second position. 7

6. An adjustable impact casing, as set forth in claim 1, wherein said means for movably positioning said first segments and second segments includes a pair of rings concentrically disposed about the axis of said casing and located radially outwardly from said first segments and second segments, one of said rings located above the other said ring, linkage means interconnecting one of said rings to said push rods for displacing said first segments and the other of said rings to said push rods for displacing said second segments, first adjustment drive means connected to and extending between each of said rings for moving one of said rings in the axial direction of said casing relative to the other, second adjustment drive means connected to the other of said rings and supported on said casing at a point spaced in the axial direction of said casing from said first and second segments for moving the other of said rings, and control means associated with said first and second adjustment drive means for actuating said first adjustment drive means for initially axially displacing the one of said rings relative to the other said ring and moving the ones of said first segments and second segments associated therewith through such linkage means into spaced relationship, followed by actuating said second adjustment drive means for displacing the other of said rings and through said first adjustment drive means the one of said rings in the same direction at the same time for moving said first segments and said second segments toward the second position and for locating the one of said first segments and second segments interconnected through said linkage means to said ring to which said second adjustment means is connected into the second position and finally actuating said first adjustment drive means for displacing the one of said rings and the ones of said first segments and second segments associated therewith into contact with the other ones of said first segments and second segments already located in the second position.

7. An adjustable impact casing, as set forth in claim 6, wherein said first adjustment drive means comprises a first hydraulic cylinder-piston rod assembly connected at one end to one of said rings and at its opposite end to the other said ring and said second adjustment drive means comprises a second hydraulic cylinder-piston rod assembly connected at one end to said casing and at its opposite end to the other one of said rings. 

1. An adjustable impact casing for use in a shaft furnace, particularly in a blast furnace, said casing having an upright axis and comprising a plurality of angularly spaced apart first arcuate segments forming an inner row about the casing axis, a plurality of angularly spaced apart second segments forming an outer row about the casing axis and disposed contiguous to said inner row, the axes of said first segments and second segments extending in the direction of the casing axis and offset relative to one another and said first segments and second segments having their lateral edges extending in the direction of the casing axis arranged in overlapping substantially contacting relationship so that said inner row and outer row of segments form a continuous casing surface, means for supporting said first and second segments, each of said first and second segments pivotally mounted on said means adjacent the upper ends of the segments, a plurality of push rods extending transversely of the casing axis and each said push rod secured to a different one of said first and second segments, wherein the improvement comprises means for movably positioning said first and second segments from a first position to a second position in both of which positions said first segments and second segments are in contact by initially displacing one of said first segments and second segments from the first position out of contact from and into spaced relationship with the other then displacing said first segments and second segments together in the same spaced relationship toward the second position and locating one of said first and second segments in the second position at the completion of the second displacement and thirdly displacing the other one of said first segments and second segments into the second position and into contact with the one of said first segments and second segments located in the second position.
 2. An adjustable impact casing, as set forth in claim 1, wherein said means for movably positioning said first segments and second segments includes control means for effecting the time sequence of the initial displacement, second displacement and third displacement of said first segments and second segments.
 3. An adjustable impact casing, as set forth in claim 1, wherein said means for movably positioning said first segments and second segments includes a pair of rings concentrically disposed about the axis of said casing and located radially outwardly from said first segments and second segments, one of said rings located above the other said ring, linkage means interconnecting one of said rings to said push rods for displacing said first segments and the other of said rings to said push rods for displacing said second segments, first adjustment drive means connected to one of said rings for moving said ring in the axial direction of said casing, second adjustment drive means connected to the other of said rings for moving said ring in the axial direction of said casing, and control means associated with said first and second adjustment means for initially displacing one of said first and second segments out of contact with one another followed by moving both of said first and second segments together and finally displacing the other one of said first and second segments into contact with the other.
 4. An adjustable impact casing, as set forth in claim 3, wherein said first adjustment drive means comprises a first hydraulic cylinder-piston rod assembly connected at one end to said casing and at its other end to the one of said rings and sAid second adjustment drive means comprises a second hydraulic cylinder-piston rod assembly connected at one end to said casing and at its other end to the other said ring.
 5. An adjustable impact casing, as set forth in claim 1, wherein said means for movably positioning said first segments and second segments includes a pair of rings concentrically disposed about the axis of said casing and located radially outwardly from said first segments and second segments, one of said rings located above the other said ring, linkage means interconnecting one of said rings to said push rods for displacing said first segments and the other of said rings to said push rods for displacing said second segments, first adjustment drive means connected to one of said rings for moving said ring in the axial direction of said casing, second adjustment drive means connected to the other of said rings for moving said ring in the axial direction of said casing, and control means associated with said first and second adjustment means for initially displacing the ones of said first segments and second segments closer to the second position in the direction of the second position in spaced relationship to the other ones of said first segments and second segments, followed by moving both of said first segments and second segments together until the other ones of said first segments and second segments are in the second position and finally displacing the ones of said first segments and second segments in the opposite direction into the second position and into contact with the other ones of said first segments and second segments located in the second position.
 6. An adjustable impact casing, as set forth in claim 1, wherein said means for movably positioning said first segments and second segments includes a pair of rings concentrically disposed about the axis of said casing and located radially outwardly from said first segments and second segments, one of said rings located above the other said ring, linkage means interconnecting one of said rings to said push rods for displacing said first segments and the other of said rings to said push rods for displacing said second segments, first adjustment drive means connected to and extending between each of said rings for moving one of said rings in the axial direction of said casing relative to the other, second adjustment drive means connected to the other of said rings and supported on said casing at a point spaced in the axial direction of said casing from said first and second segments for moving the other of said rings, and control means associated with said first and second adjustment drive means for actuating said first adjustment drive means for initially axially displacing the one of said rings relative to the other said ring and moving the ones of said first segments and second segments associated therewith through such linkage means into spaced relationship, followed by actuating said second adjustment drive means for displacing the other of said rings and through said first adjustment drive means the one of said rings in the same direction at the same time for moving said first segments and said second segments toward the second position and for locating the one of said first segments and second segments interconnected through said linkage means to said ring to which said second adjustment means is connected into the second position and finally actuating said first adjustment drive means for displacing the one of said rings and the ones of said first segments and second segments associated therewith into contact with the other ones of said first segments and second segments already located in the second position.
 7. An adjustable impact casing, as set forth in claim 6, wherein said first adjustment drive means comprises a first hydraulic cylinder-piston rod assembly connected at one end to one of said rings and at its opposite end to the other said ring and said second adjustment drive means comprises a second hydraulic cylinder-piston rod assembly connected at one end to said casing and at its opposite end to the other one of said rings. 